MORRIS TOWNSHIP, N.J. — The white-brick monastery across a busy street from a Shell service station seems an unlikely place for a confrontation that now involves Mother Teresa, the Nobel Peace Prize winner, and that ultimately may be decided by Pope John Paul II.

It is a dispute so heated that police have been summoned twice to separate feuding nuns. For the last eight days, five conservative nuns--protesting what they see as serious erosion of their sheltered, prayerful life style that dates back to the 16th Century--have barricaded themselves in the infirmary of the Monastery of the Most Blessed Virgin Mary of Mt. Carmel.

At issue are such worldly temptations as the introduction by a new mother superior of a television set and a videotape recorder into the monastery, too extravagant menus and the placing of spotlights in a normally dimly lit prayer area. The protesters also say that they fear church authorities plan to sell the monastery to real estate developers. They view their entire way of life as under siege.

"It is a real estate issue at the expense of our lives and vocations," charged Sister John of the Cross, in a telephone interview with The Times Wednesday night from the infirmary where she and the other nuns are barricaded. ". . . TV is only one concrete thing. It is a total breakdown of our entire life style, whether it be from food to clothing to recreation to prayer.

"We are an austere order. That austerity is gone," Sister John charged further. "It has become very self-indulgent."

On Wednesday, Bishop Frank J. Rodimer of the Diocese of Paterson, N.J., announced that a special Vatican emissary had been appointed to mediate the dispute. He said that the church's Congregation for the Religious in Rome had assigned Father Kevin Culligan, a Carmelite priest from Milwaukee, to meet with both sides. But he also chastised the protesting nuns, calling them "disobedient," their actions a "scandal" and accused them of disseminating "half-truths or no truths at all." He denied any plan to sell the monastery.

"They have broken their vows of obedience," Rodimer charged.

But, declared Sister John: "We want to make it clear we are not disobedient. We are obedient. I sit here . . . with the rule of Canon law. It appears we are disobeying the bishop. We are obeying the laws of the church.

Objectivity Challenged

"Bishop Rodimer has ignored the fact we have a case pending in Rome. He has not contacted our defender," Sister John told The Times. "With regard to Father Culligan, we know he has liberal views and is a personal friend of Mother Teresa Hewitt (the present mother superior of the monastery). We question his objectivity."

For more than six decades, the red-roofed monastery has been a fixture in this wealthy New Jersey suburban community. Township Police Chief Robert M. O'Connor remembers hearing the monastery's bells toll as a child, a signal to townspeople that the cloistered Carmelite nuns--who almost never venture out into the world--had run out of food.

Parishioners would respond to the call, a practice that continues today as friends of the nuns enter a vestibule, tug hard at a rope to ring an interior bell and push food through a small brown wooden revolving window.

In such an atmosphere, O'Connor said, he was amazed when policemen were summoned to the monastery to intercede in the long-simmering dispute.

"There had been a report of some kind of trouble at the monastery," O'Connor explained in an interview in his office. "We went over there and talked to the sisters. There was nothing we could do. It was a civil matter of residency."

Mother Teresa Vows to Help

On Monday, the protesting sisters received encouragement in their dispute when Mother Teresa of Calcutta, the 1979 Nobel Peace Prize winner, telephoned them to pledge her support. Mother Teresa said that she would intercede with the Pope when she visits the Vatican soon. Mother Teresa had been contacted by a New Jersey newspaper and told of the trouble.

"Mother Teresa encouraged us and said she would go to the Holy Father on our behalf," Sister John told The Times. "She said everything would be all right. It was really breathtaking. We were quite moved to know she was so concerned about us."

The nuns also have engaged a canon lawyer to press their case in the Vatican courts.

Scholars say that the dispute mirrors a broader clash between traditionalists and reformers in cloistered Carmelite monasteries. Most of the 65 Carmelite cloisters in the United States have begun to follow changes brought to the church by Vatican II in the 1960s. But strong pressures also exist for a strictly contemplative life style.

The 13 nuns inside the Monastery of the Most Blessed Virgin Mary of Mt. Carmel belong to the Discalced Order of Carmelites, a highly sheltered order founded in the 16th Century. It is devoted to prayer and penance. Nuns are permitted to speak to visitors only through a grillwork and generally remain all their lives in the convent they first enter.